Water quality criteria are the standards of boundary in terms of chemical, physical and biological parameters to achieve the proper water usage. It is also the term to describe how protected the water system is.

Maximum Contaminant level is the limit or borderline (maximum) concentraton of chemical component in water that is being consumed by living organisms preferably humans. This means that for a certain element, compound, ion, it has a specific limit of concentration that will make it lethal or toxins to organisms (prefferably to humans).